Electricity Lab using Kill-A-Watt Meters

Last summer, I received a grant for Kill-A-Watt meters and implemented this new lab.  It teaches students about electricity, watts, math and conservation using Kill-A-Watt meters. The kids were SUPER engaged (so were adults who came by) and it was highly relevant for not only their lives, but the energy concepts they need to know.  My AP Environmental Science students did the lab, but the AP Physics B teacher will also use this year.

Click for a copy of the lab.

You will need to alter the copy to reflect the cost of electricity in your town and the specific appliances that you have or want to use in lab.

Supplies Needed

  • Kill-A-Watt Meters:  I had one meter per lab table with two items to test at each table.  I ordered the Kill-A-Watt EZ model from Amazon.  But, I also like the regular model too.   The EZ model lets kids see the cost of electricity more easily, but the regular model is easier to use and find the “watts”setting.  Either are fine for this lab. (But, if you use my write-up, be sure to change some of the instructions if using the regular model).

In order to afford 10 of them, I wrote a grant request on Donors Choose and was funded in a few days by two corporate sponsors.  Here is a post about my favorite ways to find funding for new labs. 

  • Various appliances from your science room or from home.
  • Power Strips (optional).  The plugs in my lab are on the sides of the tables so I found power strips were very helpful. That way all the kids in a group could see the meter when it was plugged in.  I ordered a few of these to have ready next year.  If your’e writing a grant, be sure to add a few of these, if needed in your lab.

    The plugs in my lab are on the sides of the tables which means only 1 person out of 4 could see the meter AND they’d have to turn sideways to do it. Instead, I placed a powerstrip on each table to bring the meter to the top and all kids could read the meter.
  • Christmas lights (optional, but really engaging for the kids) .  I was fortunate to find regular and Energy start Christmas lights at Target in October, but I couldn’t find LED lights so I ordered online.  They were pricey, but I only needed 1 strand and it will last for several years for this lab. (And I can use to decorate my classroom for Christmas!)

    LED, Energy Star, and regular Christmas lights. All were 100 count strands for comparison.

Lab Setup

I had two devices per lab table and meter.  The students rotated from table to table.  I utilized items in the lab whenever possible, like this TV.

The two appliances at this station were the mounted TV and a portable heater.
Large and Small Battery Chargers. The larger one drew more watts, but is also a rapid charger.
Safety warning for the space heater. The heater isn’t dangerous as it has safety mechanisms, but I put a note on just as a precaution.
Apple phone charger and a Micro USB charger. The kids plugged in their own phones. They needed to try two different devices.  Some groups only had iPhones so they had to compare models.
Goggles sterilizer and microwave. It was interesting that the goggles sterilizer (UV light) used the same wattage when plugged it whether it was turned on or off.
A blow dryer on high, low, hot and cold made interesting data.

Data-Explore section

Students took data on a chart and then created a graph.  I had a Kill-A-Watt meter set up at each lab table along with 2-3 appliances and then set a timer for kids to rotate every 4-5 minutes.  I had 9 tables and it took about 45 minutes to rotate to every table.

If kids finished that station before the timer, they worked on the bar graph of their data chart.

The LED desk light only drew 2.8 Watts

Explain-Vampire Power and Conservation

I showed a couple of videos helping explain some of the data that kids see.  I wanted them to notice the appliances that still drew power even when not turned on.  Many students have never heard of this.  I also wanted them to see good examples of energy conservation.

Elaborate–Math Calculations

Kids did A LOT of practice with energy math–which they need for the AP Exam.  It is also needed in real life.  In addition, they discussed the environmental and human health costs of electricity.

 

 

 

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